Resumo

The present work reports a novel numerical approach to modeling of melting processes. It combines the enthalpy method for solid-liquid phase change with motion of the solid phase which may be caused by forcing or gravity/buoyancy. Recently, an improved enthalpy method that is coupled with solid sinking motion was suggested by the authors. This approach modeled the flow between the solid phase and the hot surface, but it did not take into account thermal convection in the melt. In the current work, a new general formulation for the enthalpy method is suggested. This new approach allows proper modeling of the natural convection in the melt, without any need for an arbitrary mushy constant or effective viscosity. Moreover, the model is suitable for constrained melting, where the solid phase is stagnant, or unconstrained melting, where the solid is allowed to move. For the latter case, the interaction between the solid bulk motion and the flow in the melt can be coupled by the force balance on the solid phase. The model is realized via an original in-house numerical code. Some case studies are presented and discussed.